Sensor assembly and method of detecting position of a target through multiple structures

ABSTRACT

A sensor assembly includes a first structure and a second structure disposed radially outwardly of the first structure. Also included is a sensor body extending through the first and second structures, the sensor body having first and second ends, the second end disposed in an ambient environment. Further included is a sensor mounted to the sensor body proximate the second end, the sensor configured to detect a characteristic of a target disposed within the first structure. Yet further included is a first sealing assembly configured to operatively couple the sensor body to the second structure and to accommodate movement of the sensor body. The first sealing assembly includes a mounting body, a radial seal, a slider plate and a slider plate retainer disposed in a recess of the mounting body and in abutment with the slider plate.

FEDERAL RESEARCH STATEMENT

The invention disclosed herein was made with Government support underContract No. N00014-09-D-0821 with the United States Navy. TheGovernment may have certain rights in the subject matter disclosedherein.

BACKGROUND OF THE INVENTION

The embodiments herein generally relate to sensor assemblies and, moreparticularly, to a sensor assembly extending through a plurality ofstructures which separate distinct operating environments, as well as amethod of detecting position of a target through multiple structures.

Adjustable guide vanes within compressor sections of a turbine engineare known and are able to be monitored with sensing equipment. Sensingequipment in a turbine section of a gas turbine engine poses morechallenges due to a high temperature and pressure environment therein.Typically, a hot gas path of a turbine section is surrounded by multiplelayers of structures that are subjected to distinct thermal growthcycles due to the distinct environments defined by each structure.Challenges with sensing include operating in extreme hot pressurizedenvironments and bringing the signal out to the outer surface of theengine through multiple engine sections. The distinct thermal growthrates noted above are combined with tolerance stacking of the varioushardware pieces.

BRIEF DESCRIPTION OF THE INVENTION

According to one embodiment, a sensor assembly includes a firststructure defining a first interior volume having a first environmentwith a first temperature and a first pressure. Also included is a secondstructure disposed radially outwardly of the first structure anddefining a second interior volume having a second environment with asecond temperature and a second pressure each lower than the firsttemperature and the first pressure. Further included is a sensor bodyextending through a first aperture of the first structure and a secondaperture of the second structure, the sensor body having a first end anda second end, the first end disposed within the first environment andthe second end disposed in an ambient environment located radiallyoutwardly of the second structure, wherein the ambient environment hasan ambient temperature and an ambient pressure each lower than thesecond temperature and the second pressure. Yet further included is asensor mounted to the sensor body proximate the second end of the sensorbody, the sensor configured to detect at least one characteristic of atarget disposed within the first environment. Also included is a firstsealing assembly configured to operatively couple the sensor body to thesecond structure and to accommodate movement of the sensor body due torelative movement between the first structure and the second structure.The first sealing assembly includes a mounting body coupled to thesecond structure and a radial seal disposed in a groove of the sensorbody. The first sealing assembly also includes a slider plate having acylindrical portion and a ring portion, the cylindrical portion and thering portion disposed substantially orthogonal to each other, thecylindrical portion disposed in abutment with the radial seal. The firstsealing assembly further includes a slider plate retainer disposed in arecess of the mounting body and in abutment with the ring portion of theslider plate to fix the slider plate.

According to another embodiment, a method of detecting position of atarget through multiple structures separating multiple distinctenvironments is provided. The method includes penetrating a plurality ofstructures with a sensor body, a first end of the sensor body beingdisposed within a first interior volume having a first environment witha first temperature and a first pressure, a second end of the sensorbody being disposed in an ambient environment having an ambienttemperature and an ambient pressure each lower than the firsttemperature and the first pressure, the second end having a sensormounted thereto. The method also includes operatively coupling thesensor body to at least one of the plurality of structures with asealing assembly. The method further includes accommodating relativemovement between the plurality of structures in the radial directionwith a radial seal of the sealing assembly, the radial seal disposedwithin a groove of the sensor body. The method yet further includesaccommodating relative movement between the plurality of structures inthe circumferential direction and the axial direction with a sliderplate of the sealing assembly, the slider plate having a cylindricalportion and a ring portion, the cylindrical portion and the ring portiondisposed substantially orthogonal to each other, the cylindrical portiondisposed in abutment with the radial seal and the ring portion disposedwithin a recess of a mounting body coupled to one of the plurality ofstructures.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter which is regarded as the invention is particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The foregoing and other features and advantages ofthe invention are apparent from the following detailed description takenin conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view of a portion of a turbine section having aplurality of structures separating a plurality of volumes havingdistinct operating environments; and

FIG. 2 is a partial cross-sectional view of a sensor assembly extendingthrough the plurality of structures of the turbine section.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, a portion of a turbine section is illustrated andgenerally referenced with numeral 10. In an exemplary embodiment, theturbine section 10 is part of an aircraft engine, such as a highpressure turbine or a low pressure turbine. Illustrated is a portion ofa single stage of the turbine section 10. Included is a plurality ofadjustable vanes 12, such as adjustable stator vanes and which may bereferred to interchangeably, that are configured to rotate in acontrollable manner. The number of stator vanes within a single stagemay vary depending upon the application. In one embodiment, the numberof stator vanes varies from about 20 vanes to about 40 vanes. Rotationof the adjustable stator vanes 12 is desirable due to increasedefficiency and performance of the aircraft engine. Specifically, theadjustable stator vanes 12 may be rotated to optimal anglescorresponding to different operating conditions of the aircraft engine.For example, improvements in specific fuel consumption are seen byadjusting the vanes based on certain operating conditions. Segments ofthe guide vanes 12 are typically rotated concurrently by a linkagemechanism or the like that includes a crank arm or other mechanicalstructure operatively coupled to the guide vanes 12. It is to beappreciated that all or only some of the total number of vanes within astage may be rotatable. For example, in some embodiments, only half ofthe total vanes are rotatable. In such an embodiment, every other vanemay be rotated. As one can understand, any fraction of the total numberof vanes may be rotated and the spacing between the vanes that areadjustable may vary. Numerous contemplated combinations may be suitablefor different embodiments.

The adjustable stator vanes 12 are disposed within a first interiorvolume 14 having a harsh operating environment (also referred to hereinas a first environment) where a hot gas passes over them in an effort toconvert the thermal energy of the hot gas to mechanical work forpropulsion of the aircraft. The first interior volume 14 is defined by afirst structure 16, such as a turbine casing, and the first environmenthas a first temperature and a first pressure. The precise temperatureand pressure will vary depending upon the type of aircraft engine andthe operating conditions, but reference to the first temperature and thefirst pressure will be appreciated based on their values relative toother environments of other volumes discussed herein. Disposed radiallyoutwardly of the first structure 16 is a second structure 18, such as aninner casing. An inner surface of the second structure 18 and an outersurface of the first structure 16 define a second interior volume 20.The second interior volume 20 has a second environment therein, with thesecond environment having a second temperature and a second pressure.The precise temperature and pressure of the second environment will varydepending upon the type of aircraft engine and the operating conditions,but irrespective of those variables, the second temperature and thesecond pressure are lower than the first temperature and the firstpressure, respectively. Disposed radially outwardly of the secondstructure 18 is a third structure 22, such as an outer casing. An innersurface of the third structure 22 and an outer surface of the secondstructure 18 define a third interior volume 24. The third interiorvolume 24 has a third environment therein, with the third environmenthaving a third temperature and a third pressure. The precise temperatureand pressure of the third environment will vary depending upon the typeof aircraft engine and the operating conditions, but irrespective ofthose variables, the third temperature and the third pressure are lowerthan the second temperature and the second pressure, respectively. Anambient environment 23 is located radially outwardly of the thirdstructure 22. The ambient environment 23 has an ambient temperature andan ambient pressure that are lower than the third temperature and thethird pressure, respectively. It is to be understood that more or lessstructures, and therefore volumes with different environments, may bepresent. The embodiments described herein benefit multi-layer structureswith different environments, as will be appreciated from the descriptionbelow.

Although the structures, volumes and environments described above andillustrated are in the context of an aircraft engine, it is to beappreciated that any structure requiring separation of multiple volumesthat are subjected to distinct environments will benefit from theembodiments described herein.

Referring now to FIG. 2, with continued reference to FIG. 1, a sensorassembly 30 configured to penetrate multiple structures is illustratedin detail. The sensor assembly 30 may be used in conjunction with anystructure or assembly that has a plurality (i.e., two or more) ofstructures that define multiple distinct environments. The sensorassembly 30 is operatively coupled to each of the plurality ofstructures and includes features that accommodate relative movementbetween the plurality of structures that occurs due to the distinctoperating environments.

In the illustrated exemplary embodiment of FIG. 1, the sensor assembly30 penetrates structures of the turbine section 10 and is subjected tothe distinct environments that are defined by those structures. Inparticular, the sensor assembly 30 includes a sensor body 32 thatpenetrates through apertures of at least two structures, such as a firstaperture of the first structure 16, a second aperture of the secondstructure 18 and a third aperture of the third structure 22. It is to beappreciated that the sensor body 32 may penetrate only two structuresand may penetrate more than the three illustrated structures as well,depending upon the particular structure or assembly that the sensorassembly 30 is employed with. The sensor body 32 extends from a firstend 34 to a second end 36. The first end 34 is disposed radiallyinwardly proximate the first structure 16 and is operatively coupledthereto. Coupling of the first end 34 of the sensor body 32 to the firststructure 16 may be facilitated in any known securing process, such aswelding, mechanical fasteners or threaded connection. The first end 34may protrude slightly into the first interior volume 14, such that it isexposed to the first environment.

Sensor instrumentation (not illustrated) is located proximate the firstend 34 and is routed along an interior cavity 38 of the sensor body 32that is defined by an interior wall 40 of the sensor body 32. Theinterior cavity 38 may be formed of any suitable geometry, such ascylindrical, for example. The interior cavity 38 provides a protectedpath for the sensor instrumentation to be routed from the first end 34,where sensing detection is made, to the second end 36 of the sensor body32, where a sensor 42 is operatively coupled. The sensor 42 may becoupled to the sensor body 32 proximate the second end 36 in anysuitable manner. The second end 36 is disposed outside of the firstinterior volume 14. In the exemplary embodiment, the second end 36 ofthe sensor body 32, and therefore the sensor 42, is located in theambient environment 23 radially outwardly of the third structure 22, butplacement of the sensor 42 in one of the more benign environments (e.g.,second interior volume 20 or third interior volume 24) is contemplated.Placing the sensor 42 in a location outside of the harsh environment ofthe first interior volume 14, and possibly outside of the second andthird interior volumes 20, 24, allows for a wider selection of sensors.Wider selection is available based on certain sensors having sensitivelimitations on the operating environments in which they may be disposed.

The sensor 42 is connected to the sensor instrumentation that is able towithstand the harsher environment of the first interior volume 14. Thesensor instrumentation is configured to detect at least onecharacteristic of a target 13, such as the adjustable stator vanes 12disposed within the first interior volume 14. The terms target andadjustable stator vanes 12 may be used interchangeably herein as thetarget 13 and the vane may be a, single integrally formed structure ormay be distinct components that are operatively coupled to each other ina fixed manner, such that rotation of the vane imparts correspondingrotation of the target. “At least one characteristic” refers to anycharacteristic that is commonly measured by sensors. For example,position of the target, temperature of the target and pressure proximatethe target are all examples of characteristics that may be detected bythe sensor 42. In an exemplary embodiment, the sensor 42 is configuredto detect an angular position of the target 13 via signals generatedfrom the sensor instrumentation located proximate the first end 34 ofthe sensor body 32.

Remotely locating the sensor 42 in a less harsh environment, such as theambient environment 23, ensures accurate and reliable operation of thesensor 42, thereby providing more accurate measurements. However,relative movement of the plurality of structures that the sensorassembly 30 penetrates and is operatively coupled to leads to potentialdetrimental effects related to accuracy and reliability of themeasurements. The relative movement is attributed to effects of thedistinct operating environments, such as different thermal growth ratesof the structures. The relative movement of the structures, 16, 18, 22,may be in the radial, axial and/or circumferential direction.

To accommodate the relative movement of the structures, one or moresealing assemblies are provided to operatively couple the sensor body 32to respective structure(s). The number of sealing assemblies will dependupon the number of structures to which the sensor body 32 is topenetrate and to be operatively coupled to.

In the illustrated embodiment, operative coupling of the sensor body 32to the first structure 16 is made by a mechanical process, such as athreaded connection, as described in detail above. The sensor body 32 isoperatively coupled to the second structure 18 with a first sealingassembly 50.

The first sealing assembly 50 includes a radial seal 52 that is disposedin a groove 54 of the sensor body 32. The groove 54 extendscircumferentially around an outer surface 56 of the sensor body 32 in aradial location proximate that is at the radial location of the secondstructure 18. The groove 54 extends completely around the sensor body32. The radial seal 52 is configured to be at least partially disposedwithin the groove 54 and is in abutment with a radial seal backer 58that is sandwiched between the radial seal 52 and a radial seal retainer60. The radial seal retainer 60 is disposed in a notch 62 of the sensorbody 32. As with the radial seal 52, the radial seal backer 58 and theradial seal retainer 60 each extend completely around the sensor body32. The abutment of the radial seal retainer 60 and the radial sealbacker 58, in combination with the abutment of the radial seal backer 58and the radial seal 52, biases the radial seal 52 to fix the radial seal52 in a radial direction. The radial seal retainer 60 is typically asubstantially rigid structure, such that stiff support of the radialseal 52 is achieved. The radial seal 52 is at least partially flexiblein order to accommodate relative movement of the structures in a radialdirection, thereby allowing the sensor body 32 to move slightly in theradial direction, while maintaining a sealed arrangement.

The first sealing assembly 50 also includes a slider plate 64. Theslider plate 64 is a single, integrally formed structure that includes acylindrical portion 68 and a ring portion 70. The cylindrical portion 68extends circumferentially around the sensor body 32 and, moreparticularly, around the radial seal 52. The cylindrical portion 68 isin abutment with the radial seal 52 to fix the radial seal 52 in axialand circumferential directions. The ring portion 70 is orientedsubstantially perpendicularly to the cylindrical portion 68 and isdisposed in contact with a radially inner surface of a mounting body 90that is coupled to the second structure 18. As shown in the illustratedembodiment, the mounting body 90 may be a ring-like structure thatdirectly mounts to the second structure 18 via mechanical fasteners 92,however, alternative geometries and coupling processes may be employed.The mounting body 90 may be a single ring that extends circumferentiallyaround the entire sensor body 32 or may be segmented. A slider plateretainer 72 is disposed within a recess 74 of the mounting body 90 andis in abutment with the slider plate 64 to fix the slider plate in aradial direction. The slider plate retainer 72 is typically asubstantially rigid structure, such that stiff support of the sliderplate 64 is achieved. The slider plate 64 is at least partially flexiblein order to accommodate relative movement of the structures in both thecircumferential and axial directions, thereby allowing the sensor body32 to move slightly in these directions, while maintaining a sealedarrangement.

As described in detail above, additional structures, such as the thirdstructure 22 may require penetration and operative coupling by thesensor assembly 30. In such embodiments, additional sealing assembliesidentical to that described above in conjunction with the first sealingassembly 50 are employed. For example, a second sealing assembly 80 isillustrated. The second sealing assembly 80 includes identical sealingcomponents to accommodate relative movement of the first, second andthird structures 16, 18, 22. Such components are illustrated and labeledwith corresponding numerals associated with the sealing components ofthe first sealing assembly 50. For purposes of description, additionalsealing structures are not described or illustrated, but it is to beappreciated that additional sealing assemblies may be included to coupleto additional structures.

Advantageously, the embodiments described herein allow for penetrationthrough multiple temperature and pressure environments in order tomonitor signals deep within a harsh operating environment, such as a hotgas path of a turbine engine. The embodiments also facilitate sensors tobe utilized in an LRU configuration to improve reliability and accuracyof signals from within the engine. Other benefits include the provisionof greater selection of the sensing technology that is best suited tomeet performance requirements.

While the invention has been described in detail in connection with onlya limited number of embodiments, it should be readily understood thatthe invention is not limited to such disclosed embodiments. Rather, theinvention can be modified to incorporate any number of variations,alterations, substitutions or equivalent arrangements not heretoforedescribed, but which are commensurate with the spirit and scope of theinvention. Additionally, while various embodiments of the invention havebeen described, it is to be understood that aspects of the invention mayinclude only some of the described embodiments. Accordingly, theinvention is not to be seen as limited by the foregoing description, butis only limited by the scope of the appended claims.

What is claimed is:
 1. A sensor assembly comprising: a first structuredefining a first interior volume having a first environment with a firsttemperature and a first pressure; a second structure disposed radiallyoutwardly of the first structure and defining a second interior volumehaving a second environment with a second temperature and a secondpressure each lower than the first temperature and the first pressure; asensor body extending through a first aperture of the first structureand a second aperture of the second structure, the sensor body having afirst end and a second end, the first end disposed within the firstenvironment and the second end disposed in an ambient environmentlocated radially outwardly of the second structure, wherein the ambientenvironment has an ambient temperature and an ambient pressure eachlower than the second temperature and the second pressure; a sensormounted to the sensor body proximate the second end of the sensor body,the sensor configured to detect at least one characteristic of a targetdisposed within the first environment; and a first sealing assemblyconfigured to operatively couple the sensor body to the second structureand to accommodate movement of the sensor body due to relative movementbetween the first structure and the second structure, the first sealingassembly comprising: a mounting body coupled to the second structure; aradial seal disposed in a groove of the sensor body; a slider platehaving a cylindrical portion and a ring portion, the cylindrical portionand the ring portion disposed substantially orthogonal to each other,the cylindrical portion disposed in abutment with the radial seal; and aslider plate retainer disposed in a recess of the mounting body and inabutment with the ring portion of the slider plate to fix the sliderplate.
 2. The sensor assembly of claim 1, wherein the at least onecharacteristic detected is a position of the target.
 3. The sensorassembly of claim 2, wherein the position is an angular position of thetarget.
 4. The sensor assembly of claim 1, wherein the sensor body isthreaded to the first structure.
 5. The sensor assembly of claim 1,further comprising: a radial seal backer in abutment with the radialseal; and a radial seal retainer disposed in a notch of the sensor bodyand in abutment with the radial seal backer to fix the radial seal in aradial direction.
 6. The sensor assembly of claim 5, wherein the sliderplate retainer and the radial seal retainer are each substantially rigidmembers.
 7. The sensor assembly of claim 1, wherein the radial sealaccommodates relative movement of the first structure and the secondstructure in a radial direction.
 8. The sensor assembly of claim 1,wherein the slider plate accommodates relative movement of the firststructure and the second structure in a circumferential direction and anaxial direction.
 9. The sensor assembly of claim 1, further comprising:a third structure disposed radially outwardly of the second structureand defining a third interior volume having a third environment with athird temperature and a third pressure each lower than the secondtemperature and the second pressure, wherein the ambient environment isdisposed radially outwardly of the third structure; and a second sealingassembly configured to operatively couple the sensor body to the thirdstructure and to accommodate movement of the sensor body due to relativemovement between the first structure, the second structure and the thirdstructure, the second sealing assembly comprising: a mounting bodycoupled to the third structure; a radial seal disposed in a groove ofthe sensor body; a slider plate having a cylindrical portion and a ringportion, the cylindrical portion and the ring portion disposedsubstantially orthogonal to each other, the cylindrical portion disposedin abutment with the radial seal; and a slider plate retainer disposedin a recess of the mounting body and in abutment with the ring portionof the slider plate to fix the slider plate.
 10. The sensor assembly ofclaim 9, wherein the sensor assembly is disposed in a turbine section ofan aircraft engine.
 11. The sensor assembly of claim 10, wherein thetarget is an adjustable stator vane of the turbine section.
 12. Thesensor assembly of claim 10, wherein the first structure comprises aturbine casing, the second structure comprises an inner casing and thethird structure comprises an outer casing.
 13. A method of detectingposition of a target through multiple structures separating multipledistinct environments, the method comprising: penetrating a plurality ofstructures with a sensor body, a first end of the sensor body beingdisposed within a first interior volume having a first environment witha first temperature and a first pressure, a second end of the sensorbody being disposed in an ambient environment having an ambienttemperature and an ambient pressure each lower than the firsttemperature and the first pressure, the second end having a sensormounted thereto; operatively coupling the sensor body to at least one ofthe plurality of structures with a sealing assembly; accommodatingrelative movement between the plurality of structures in the radialdirection with a radial seal of the sealing assembly, the radial sealdisposed within a groove of the sensor body; and accommodating relativemovement between the plurality of structures in the circumferentialdirection and the axial direction with a slider plate of the sealingassembly, the slider plate having a cylindrical portion and a ringportion, the cylindrical portion and the ring portion disposedsubstantially orthogonal to each other, the cylindrical portion disposedin abutment with the radial seal and the ring portion disposed within arecess of a mounting body coupled to one of the plurality of structures.14. The method of claim 13, further comprising fixing the radial seal inthe radial direction with a substantially rigid radial seal retainerdisposed within a notch of the sensor body.